Component bdlt_intervalconversionutil [Package bdlt]

Provide functions to convert between time-interval representations. More...

Namespaces
namespace	bdlt

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Detailed Description

Outline

• Purpose
• Classes
• Description
  • Usage
    • Example 1: Interfacing With an API That Uses bsls::TimeInterval

Purpose:

Provide functions to convert between time-interval representations.

Classes:

bdlt::IntervalConversionUtil

functions to convert time intervals

See also:

Component bdlt_datetimeinterval, Component bsls_timeinterval

Description:

This component provides a utility struct, bdlt::IntervalConversionUtil, that defines functions to convert between C++ value types providing different representations of time intervals, (e.g., bsls::TimeInterval and bdlt::DatetimeInterval).

Usage:

This section illustrates intended use of this component.

Example 1: Interfacing With an API That Uses bsls::TimeInterval:

Some APIs, such as bsls::SystemTime, use bsls::TimeInterval in their interface. In order to use those APIs in components implemented in terms of bdlt::DatetimeInterval, it is necessary to convert between the bsls::TimeInterval and bdlt::DatetimeInterval representations for a time interval. This conversion can be accomplished conveniently using bdlt::IntervalConversionUtil.

Suppose we wish to pass the system time -- as returned by bsls::SystemTime::nowRealtimeClock -- to a function that displays a time that is represented as a bdlt::DatetimeInterval since the UNIX epoch.

First, we include the declaration of the function that displays a bdlt::DatetimeInterval:

  void displayTime(const bdlt::DatetimeInterval& timeSinceEpoch);

Then, we obtain the current system time from bsls::SystemTime, and store it in a bsls::TimeInterval:

  bsls::TimeInterval systemTime = bsls::SystemTime::nowRealtimeClock();

Now, we convert the bsls::TimeInterval into a bdlt::DatetimeInterval using convertToDatetimeInterval:

  bdlt::DatetimeInterval timeSinceEpoch =
         bdlt::IntervalConversionUtil::convertToDatetimeInterval(systemTime);

  assert(timeSinceEpoch.totalMilliseconds() ==
                                             systemTime.totalMilliseconds());

Finally, we display the time by passing the converted value to displayTime:

  displayTime(timeSinceEpoch);